muffin

Try GARbro

Open a ticket at https://github.com/morkt/GARbro, maybe author could add WAR repack.

There are two data extraction projects exist that I haven't seen mentioned in this thread. First is arc_unpacker, a command line tool somewhat similar to arc_conv. Second is GARbro, GUI 'browser' for VN archives. They're more or less actively developing and have some new archive formats supported, like the one used in Tokyo Necro for example.